W:ET Sys_LoadDll.c

void *Sys_LoadDll( const char *name, char *fqpath,
				   int( **entryPoint ) ( int, ... ),
				   int ( *systemcalls )( int, ... ) ) {
	void *libHandle;
	void ( *dllEntry )( int ( *syscallptr )( int, ... ) );
	char fname[MAX_OSPATH];
	char  *pwdpath;
	char  *homepath;
	char  *basepath;
	char  *gamedir;
	char  *fn;
	const char*  err = NULL; // bk001206 // rb0101023 - now const
#if !defined( DEDICATED )
	char *cvar_name = NULL;
#endif

	*fqpath = 0 ;       // added 2/15/02 by T.Ray

	// bk001206 - let's have some paranoia
	assert( name );

	Q_strncpyz( fname, Sys_GetDLLName( name ), sizeof( fname ) );

// bk001129 - was RTLD_LAZY
#define Q_RTLD    RTLD_NOW

	pwdpath = Sys_Cwd();
	homepath = Cvar_VariableString( "fs_homepath" );
	basepath = Cvar_VariableString( "fs_basepath" );
	gamedir = Cvar_VariableString( "fs_game" );

	// this is relevant to client only
	// this code is in for full client hosting a game, but it's not affected by it
#if !defined( DEDICATED )
	// do a first scan to identify what we are going to dlopen
	// we need to pass this to FS_ExtractFromPakFile so that it checksums the right file
	// NOTE: if something fails (not found, or file operation failed), we will ERR_FATAL (in the checksum itself, we only ERR_DROP)
#ifndef NDEBUG
	fn = FS_BuildOSPath( pwdpath, gamedir, fname );
	if ( access( fn, R_OK ) == -1 ) {
#endif
	fn = FS_BuildOSPath( homepath, gamedir, fname );
	if ( access( fn, R_OK ) == 0 ) {
		// there is a .so in fs_homepath, but is it a valid one version-wise?
		// we use a persistent variable in config.cfg to make sure
		// this is set in FS_CL_ExtractFromPakFile when the file is extracted
		cvar_t *lastVersion;
		cvar_name = va( "cl_lastVersion%s", name );
		lastVersion = Cvar_Get( cvar_name, "(uninitialized)", CVAR_ARCHIVE );
		if ( Q_stricmp( Cvar_VariableString( "version" ), lastVersion->string ) ) {
			Com_DPrintf( "clearing non matching version of %s .so: %s\n", name, fn );
			if ( remove( fn ) == -1 ) {
				Com_Error( ERR_FATAL, "failed to remove outdated '%s' file:\n\"%s\"\n", fn, strerror( errno ) );
			}
			// we cancelled fs_homepath, go work on basepath now
			fn = FS_BuildOSPath( basepath, gamedir, fname );
			if ( access( fn, R_OK ) == -1 ) {
				// we may be dealing with a media-only mod, check wether we can find 'reference' DLLs and copy them over
				if ( !CopyDLLForMod( &fn, gamedir, pwdpath, homepath, basepath, fname ) ) {
					Com_Error( ERR_FATAL, "Sys_LoadDll(%s) failed, no corresponding .so file found in fs_homepath or fs_basepath\n", name );
				}
			}
		}
		// the .so in fs_homepath is valid version-wise .. FS_CL_ExtractFromPakFile will have to decide wether it's valid pk3-wise later
	} else {
		fn = FS_BuildOSPath( basepath, gamedir, fname );
		if ( access( fn, R_OK ) == -1 ) {
			// we may be dealing with a media-only mod, check wether we can find 'reference' DLLs and copy them over
			if ( !CopyDLLForMod( &fn, gamedir, pwdpath, homepath, basepath, fname ) ) {
				Com_Error( ERR_FATAL, "Sys_LoadDll(%s) failed, no corresponding .so file found in fs_homepath or fs_basepath\n", name );
			}
		}
	}
#ifndef NDEBUG
}
#endif

	// NERVE - SMF - extract dlls from pak file for security
	// we have to handle the game dll a little differently
	// NOTE #2: we may have found a file in fs_basepath, and if the checksum is wrong, FS_Extract will write in fs_homepath
	//   won't be a problem since we start a brand new scan next
	if ( cl_connectedToPureServer && Q_strncmp( name, "qagame", 6 ) ) {
		if ( !FS_CL_ExtractFromPakFile( fn, gamedir, fname, cvar_name ) ) {
			Com_Error( ERR_DROP, "Game code(%s) failed Pure Server check", fname );
		}
	}
#endif

#ifndef NDEBUG
	// current directory
	// NOTE: only for debug build, see Sys_LoadDll discussion
	fn = FS_BuildOSPath( pwdpath, gamedir, fname );
	Com_Printf( "Sys_LoadDll(%s)... ", fn );
	libHandle = dlopen( fn, Q_RTLD );

	if ( !libHandle ) {
		Com_Printf( "\nSys_LoadDll(%s) failed:\n\"%s\"\n", fn, dlerror() );
#endif

	// homepath
	fn = FS_BuildOSPath( homepath, gamedir, fname );
	Com_Printf( "Sys_LoadDll(%s)... ", fn );
	libHandle = dlopen( fn, Q_RTLD );

	if ( !libHandle ) {
		Com_Printf( "\nSys_LoadDll(%s) failed:\n\"%s\"\n", fn, dlerror() );

		// basepath
		fn = FS_BuildOSPath( basepath, gamedir, fname );
		Com_Printf( "Sys_LoadDll(%s)... ", fn );
		libHandle = dlopen( fn, Q_RTLD );
		if ( !libHandle ) {
			// report any problem
			Com_Printf( "\nSys_LoadDll(%s) failed:\n\"%s\"\n", fn, dlerror() );
		} else {
			Com_Printf( "ok\n" );
		}

		// not found, bail
		if ( !libHandle ) {
#ifndef NDEBUG // in debug abort on failure
			Com_Error( ERR_FATAL, "Sys_LoadDll(%s) failed dlopen() completely!\n", name  );
#else
			Com_Printf( "Sys_LoadDll(%s) failed dlopen() completely!\n", name );
#endif
			return NULL;
		}

	} else {
		Com_Printf( "ok\n" );
	}

#ifndef NDEBUG
} else {
	Com_Printf( "ok\n" );
}
#endif

	Q_strncpyz( fqpath, fn, MAX_QPATH ) ;           // added 2/15/02 by T.Ray

	dllEntry = dlsym( libHandle, "dllEntry" );
	*entryPoint = dlsym( libHandle, "vmMain" );
	if ( !*entryPoint || !dllEntry ) {
		err = dlerror();
#ifndef NDEBUG // in debug abort on failure
		Com_Error( ERR_FATAL, "Sys_LoadDll(%s) failed dlsym(vmMain):\n\"%s\" !\n", name, err );
#else
		Com_Printf( "Sys_LoadDll(%s) failed dlsym(vmMain):\n\"%s\" !\n", name, err );
#endif
		dlclose( libHandle );
		err = dlerror();
		if ( err != NULL ) {
			Com_Printf( "Sys_LoadDll(%s) failed dlcose:\n\"%s\"\n", name, err );
		}
		return NULL;
	}
	Com_Printf( "Sys_LoadDll(%s) found **vmMain** at  %p  \n", name, *entryPoint );
	dllEntry( systemcalls );
	Com_Printf( "Sys_LoadDll(%s) succeeded!\n", name );
	return libHandle;
}